Giant dielectric nanoparticles as high contrast agents for electromagnetic (em) fluids imaging in an oil reservoir

ABSTRACT

Provide are compositions and methods for electromagnetic (EM) surveying of subsurface hydrocarbon reservoirs using a giant dielectric material as a contrast agent. An injection fluid composition for EM surveying may include an aqueous fluid and giant dielectric nanoparticles having a dielectric constant of at least 10000 in the 1 Hz to 1 MHz frequency range. EM surveying of a subsurface hydrocarbon reservoirs may be performed by introducing an injection fluid having the giant dielectric nanoparticles into the subsurface hydrocarbon reservoir and generating an image of the position of the injection fluid from a transit time of emitted EM energy that traveled through the reservoir.

BACKGROUND Field of the Disclosure

The present disclosure generally relates to imaging subsurfacestructures such as hydrocarbon reservoirs and fluids located in suchreservoirs. More specifically, embodiments of the disclosure relate tocross-well and borehole-to-surface electromagnetic (EM) surveying ofsuch reservoirs and fluids.

Description of the Related Art

Cross-well and borehole-to-surface electromagnetic (EM) surveying forhydrocarbon reservoirs typically uses continuous-wave (CW) EM sourcesplaced in one borehole and receivers (such as sensors) that detect thephase and amplitude of the EM signal in a distal borehole, usingmultiple source and receiver positions. The detected data and inferredtransit times may be used with the source and receiver geometry tocreate a 2D conductivity matrix or image of the inter-well plane viainversion with ray-tracing. Some fluids (such as brine) in a hydrocarbonreservoir may be electrically conductive and may attenuate EM signals.The presence of such fluids presents significant challenges tocontinuous-wave EM surveying, as such surveying must be performed atvery low frequencies (for example, about 1 Hz to about 10 kHz) whichseverely limits cross-well imaging resolution. Moreover, presence,concentration and distribution of EM-attenuating fluids in a reservoirare generally unknown prior to investigation, further increasing thedifficulties of determining the optimal frequency for EM surveying andthe corresponding imaging accuracy.

SUMMARY

Embodiments of the disclosure generally relate to EM surveying (alsoreferred to as “EM imaging” or “EM interrogation”) of subsurfacehydrocarbon reservoirs using an injection fluid having a giantdielectric material.

The use of the giant dielectric material as a contrast agent may improvethe contrast between the injection fluid and water saturated reservoirrock or connate water. Further, the giant dielectric material contrastagent may enable the use of a broader frequency range for EM surveyingof subsurface hydrocarbon reservoirs. Additionally, in some embodiments,the giant dielectric material contrast agent may no longer require theuse of pulsed EM transmissions in EM surveying, thus allowingcommercially manufactured antennas to be used, therefore reducing thedifficulty and cost of EM surveying operations.

In one embodiment, a method of electromagnetic imaging of a subsurfacehydrocarbon reservoir is provided. The method includes introducing aninjection fluid into the subsurface hydrocarbon reservoir. The injectionfluid includes a contrast agent having a plurality of giant dielectricnanoparticles, such that the plurality of giant dielectric nanoparticleshave a dielectric constant of at least 10000 at a frequency in the rangeof 1 hertz (Hz) to 1 megahertz (Mhz). The method further includesemitting pulses of electromagnetic energy from a subsurface borehole totravel through the subsurface hydrocarbon reservoir and determining thetransit time of the emitted pulses of electromagnetic energy from aplurality of electromagnetic sensors, such that the transit time of theemitted pulses through the injection fluid is greater than the transittime of the emitted pulses through the subsurface hydrocarbon reservoirabsent the injection fluid. The method further includes generating animage of the position of the injection fluid through the subsurfacehydrocarbon reservoir based on the determined transit time. In someembodiments, the plurality of giant dielectric nanoparticles includenanoparticles of A-Cu3Ti4O12, such that A is selected from the groupconsisting of Ce, Eu, Gd, Tb, Yb, and Bi. In some embodiments, theplurality of giant dielectric nanoparticles include nanoparticles of atleast one of copper titanate (CCTO), a doped nickel oxide having adopant selected from the group consisting of Li, Ti, Fe, and V, a dopedcupric oxide having a dopant selecting from the group Ta, Ca, and Ba,barium titanate, and bismuth strontium titanate. In some embodiments,the plurality of giant dielectric nanoparticles comprise an amount inthe range of 1 weight % of the total weight (w/w %) to 10 w/w %. In someembodiments, the injection fluid comprises an aqueous fluid. In someembodiments, emitting pulses of electromagnetic energy from a subsurfaceborehole to travel through the subsurface hydrocarbon reservoircomprises emitting of electromagnetic energy from at least onetransmitter positioned in the subsurface borehole. In some embodiments,the subsurface borehole comprises a first subsurface borehole, whereinthe plurality of electromagnetic sensors are positioned in a secondsubsurface borehole. In some embodiments, the plurality ofelectromagnetic sensors are positioned on the surface. In someembodiments, the image comprises a 2-D spatial map. In some embodiments,generating an image of the position of the injection fluid through thesubsurface hydrocarbon reservoir based on the determined transit timecomprises performing an inversion of the determined transit time. Insome embodiments, the method includes forming the injection fluid bymixing an aqueous fluid with the plurality of giant dielectricnanoparticles. In some embodiments, the method includes identifying asubsurface feature in the subsurface hydrocarbon reservoir based on theimage.

In another embodiment, an injection fluid composition for the imaging ofa subsurface hydrocarbon reservoir is provided. The injection fluidcomposition includes an aqueous fluid and a contrast agent having aplurality of giant dielectric nanoparticles, such that the plurality ofgiant dielectric nanoparticles have a dielectric constant of at least10000 at a frequency in the range of 1 hertz (Hz) to 1 megahertz (Mhz).In some embodiments, the plurality of giant dielectric nanoparticlescomprise nanoparticles of A-Cu3Ti4O12, such that A is selected from thegroup consisting of Ce, Eu, Gd, Tb, Yb, and Bi. In some embodiments, theplurality of giant dielectric nanoparticles comprise nanoparticles of atleast one of copper titanate (CCTO), a doped nickel oxide having adopant selected from the group consisting of Li, Ti, Fe, and V, a dopedcupric oxide having a dopant selecting from the group Ta, Ca, and Ba,barium titanate, and bismuth strontium titanate. In some embodiments,the plurality of giant dielectric nanoparticles comprise an amount inthe range of 1 weight % of the total weight (w/w %) to 10 w/w %. In someembodiments, the aqueous fluid comprises fresh water or seawater.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a transmitter-receiver array for aborehole-to-borehole electromagnetic survey in accordance with anembodiment of the disclosure;

FIG. 2 is a schematic diagram of a transmitter-receiver array for aborehole-to-surface electromagnetic survey in accordance with anembodiment of the disclosure;

FIG. 3 is a schematic diagram illustrating the time delay of EM signalsresulting from a contrast agent having a dielectric constant greaterthan saturated reservoir rock in accordance with an embodiment of thedisclosure; and

FIG. 4 is a flowchart of a process for imaging a reservoir using giantdielectric nanoparticles in accordance with an embodiment of thedisclosure.

DETAILED DESCRIPTION

The present disclosure will be described more fully with reference tothe accompanying drawings, which illustrate embodiments of thedisclosure. This disclosure may, however, be embodied in many differentforms and should not be construed as limited to the illustratedembodiments. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art.

As will be appreciated, electromagnetic (EM) surveying (also referred toas “EM imaging” or “EM interrogation”) of a reservoir relies on thedifference between the velocity of an EM wave though a contrast agent ascompared to the velocity of the EM wave through a surroundingenvironment (for example, water saturated reservoir rock). The velocityof an EM wave may be determined according to Equation 1:

$\begin{matrix}{V = \frac{c}{\sqrt{ɛ_{r}\mu_{r}}}} & (1)\end{matrix}$

Where V is the wave velocity, c is the speed of light in a vacuum, ε_(r)is the dielectric constant, and μ_(r) is the relative magneticpermeability. For example, inside a produced reservoir, the EM velocityis determined by the ε_(r) and μ_(r) of the water and reservoir rock andis dependent on the amount of water saturation. In one example, anaverage values for water saturated sand with a 20% porosity may beε_(r)=3.5 and μ_(r)=1. Thus, the velocity of the EM wave through a watersaturated reservoir may be slowed by √{square root over (3.5)}.

Accordingly, if an injected water moving through a reservoir during awaterflooding operation has an EM velocity greater than the watersaturating the reservoir rock, the injected water may be tracked astransmitted and received EM waves travel slower through the injectedwater than through the static water already saturating the reservoirrock. As discussed in the disclosure, this time delay may be measureddirectly by cross-well (also referred to as borehole-to-borehole) orborehole-to-surface measurements. Larger time delays between an EMtransmitter and receiver implies a slower EM velocity as compared to theEM velocity through existing reservoir rock and static water saturatingthe rock. In this manner, the injected water may be tracked by itscontrast in EM wave velocity as it travels through the reservoir.

Embodiments of the disclosure include injection fluid compositions forEM surveying that include giant dielectric materials. In someembodiments, an injection fluid may include an aqueous fluid and giantdielectric nanoparticles. As used in the disclosure, the term “giantdielectric” refers to materials having a dielectric constant of at least10000 (for example, in the range of 10000 to 1000000) in the 1 hertz(Hz) to 1 megahertz (Mhz) frequency range. In some embodiments, thegiant dielectric nanoparticles may include nanoparticles of A-Cu3Ti4O12(where “A” includes a trivalent rare earth element, such as Ce, Eu, Gd,Tb, Yb, or may include Bi) compounds such as calcium copper titanate(CCTO), nanoparticles of doped nickel oxides (for example, nickel oxidesdoped with Li, Ti, Fe, or V), nanoparticles of doped cupric oxides (forexample, cupric oxides doped with Ta, Ca, or Ba), nanoparticles ofbarium titanate, and nanoparticles of bismuth strontium titanate. Insome embodiments, the giant dielectric materials may includepolymer-based carbon nanotube composites. In some embodiments, aninjection fluid for use in EM surveying may include the giant dielectricmaterials described in the disclosure in an amount of at least 1 weight% of the total weight (w/w %).

Embodiments of the disclosure further include EM surveying of ahydrocarbon reservoir using an injection fluid having giant dielectricnanoparticles as a contrast agent. The injection fluid may be introducedinto the reservoir, such as via a borehole of an injection well. In someembodiments, one or more transmitter and one or more receivers may bepositioned to measure directly by cross-well (also referred to asborehole-to-borehole) or borehole-to-surface arrangements. EM energythat travels through the reservoir may be emitted from the one or moretransmitters and detected by the one or more receivers. The transit timeof the EM energy is a function of the EM velocity and is thus greaterfor EM energy traveling through the injection fluid with the highcontrast agent. The transit time of the EM energy may be determined andused to generate an image of the position of the injection fluid and, insome embodiments, identify subsurface features present in a reservoir.

FIG. 1 is a schematic diagram 100 of a transmitter-receiver arrangementfor a borehole-to-borehole EM survey in accordance with an embodiment ofthe disclosure. As will be described infra, a number of EM energymeasurements are performed with different combinations of transmitterand receiver locations in order to sample various parts of the reservoirfrom different directions, as shown in FIG. 1. The example shown in FIG.1 depicts a transmit borehole 102 and a receiver borehole 104. In someembodiments, the transmit borehole 102 may be borehole of an injectionwell and the receiver borehole 104 may be a borehole of a producingwell. In other embodiments, the transmit borehole 102 may be borehole ofa producing well and the receiver borehole 104 may be a borehole of aninjection well.

As shown in FIG. 1, one or more transmitters 106 may be positioned inthe transmit borehole 102 to emit EM energy (represented by lines 108)to travel through subsurface earth formations. The one or moretransmitters 106 may include EM sources known in the art that includetime-varying capability. For example, the one or more transmitters 106may include loop antennas. In some embodiments, the current profile usedto drive the antenna may be generated by a pulse forming circuitBlumlein circuit or a type known as a thyristor circuit.

The emitted EM energy may be, after transiting the subsurface earthformations, received by one or more receivers 110 (for example, EMsensors) positioned in the receiver borehole 104. The one or morereceivers 110 may include EM sensors capable of detecting the EM energyat the strengths and frequencies emitted by the one or more transmitters106. For example, the one or more receivers 110 may include loopantennas coupled to a recording instrument or an oscilloscope component.

In some embodiments, for example, a single transmitter (TX) 106 may bepositioned in the transmit borehole 102, and a single receiver (RX) 110may be placed in the receiver borehole 104. The single transmitter 106may remain in one position (for example, position 112) while EM transitdata is collected from the six positions (for example, positions 114,116, 118, 120, 122, 124) shown in the receiver borehole 104. Aftercollection of the data, the single transmitter 106 may be moved to thesecond position (for example, position 126) shown in the transmitborehole 102 and remain in this position while EM transit data iscollected from the six positions (for example, positions 114, 116, 118,120, 122, and 124) shown in the receiver borehole 104. The transmittermay subsequently be moved to third, fourth, fifth and sixth positions(for example, positions 128, 130, 132, and 134) while EM transit data iscollected from the six positions (for example, positions 114, 116, 118,120, and 122) at shown in the receiver borehole 104. In such an exampleembodiment, a total of 36 data sets may be collected for thecombinations of transmitter and receiver.

In some embodiments, the one or more transmitters 106 and the one ormore receivers 110 may each be mounted on or a part of a wireline toolsuspending on a wireline from a surface above the boreholes 102 and 104.The wireline may be raised and lowered within the boreholes 102 or 104to various depths using devices known in the art, such as a reel anddrum apparatus in a service truck having the various components of awireline system. The wireline may include a conductor and may enabletransmission of signals between the one or more transmitters 106 and thesurface, and between the one or more receivers 110 and surface. Forexample, signals may be sent from the surface (for example, from asurface computer) to the one or more transmitters 106 in the transmitborehole 102 to control emission of EM energy. Similarly, signals may bereceived from the one or more receivers 110 at the surface (for example,by a surface computer) to acquire measurement data associated withreceived EM energy.

FIG. 2 is a schematic diagram 200 of a transmitter-receiver array for aborehole-to-surface EM survey in accordance with an embodiment of thedisclosure. Here again, a number of EM energy measurements are performedwith different combinations of transmitter and receiver locations inorder to sample various parts of the reservoir from differentdirections, as shown in FIG. The example shown in FIG. 2 depicts atransmit borehole 202 (such as a borehole of a producer well or aninjection well) and a surface 204 at which transmitted EM energy isreceived.

As shown in FIG. 2, one or more transmitters 206 may be positioned inthe transmit borehole 202 to emit EM energy (represented by lines 208)to travel through subsurface earth formations. The one or moretransmitters 206 may include EM sources known in the art that includetime-varying capability. For example, the one or more transmitters 206may include dipole antennas. In some embodiments, the current profileused to drive the antenna may be generated by a pulse forming circuitBlumlein circuit or a type known as a thyristor circuit.

The emitted EM energy may be received by one or more receivers (forexample, receiver array 210) positioned at the surface 206. The one ormore receivers of the receiver array 210 may include EM sensors capableof detecting the EM energy at the strengths and frequencies emitted bythe one or more transmitters 206. For example, the one or more receiversmay include dipole antennas coupled to a recording instrument or anoscilloscope component.

In some embodiments, for example, a single transmitter 206 may bepositioned in the transmit borehole 202. The single transmitter mayremain in one position (for example, position 212) while EM transit datais collected from the six positions (for example, positions 214, 216,218, 220, 222, and 224) provided by the receiver array 210 at thesurface 204. After collection of the data, the single transmitter 206may be moved to the second position (for example, position 226) shown inthe transmit borehole 202 and remain in this position while EM transitdata is collected from the six positions (for example, positions 214,216, 218, 220, and 222) provided by the receiver array 210 at thesurface 204. The transmitter may subsequently be moved to third, fourth,fifth and sixth positions (for example, positions 226, 228, 230, 232,and 234) while EM transit data is collected from the six positions (forexample, positions 214, 216, 218, 220, 222, and 224) provided by thereceiver array 210 at the surface 204. In such an example embodiment, atotal of 36 data sets may be collected for the combinations oftransmitter and receiver.

Similar to the embodiment described supra and illustrated in FIG. 1, theone or more transmitters 206 may be mounted on or a part of a wirelinetool suspended on a wireline from a surface above the borehole 202.Signals may be received (for example, by a surface computer) from theone or more receivers 210 located at the surface to acquire measurementdata associated with received EM energy.

As will be appreciated, multiple measurements of transmissions such asthose shown in FIGS. 1 and 2 may be summed or averaged at a transmitterand receiver pair to improve signal to noise ratios. Multipletransmitters (for example, an array) may be employed, as well asmultiple receivers (for example, an array). Transmitters and receivers,either individual or arrays thereof, may be placed at multiple locationsto survey different areas of the reservoir or survey each area fromdifferent directions.

FIG. 3 is a schematic diagram 300 illustrating the time delay of EMsignals resulting from a contrast agent having a dielectric constantgreater than saturated reservoir rock 302 in accordance with anembodiment of the disclosure. Similar to the embodiments shown in FIG. 1and discussed supra, FIG. 3 depicts one or more transmitters 304, suchas positioned in a transmit borehole, that emit EM energy (representedby lines 306 and 308) that transits through the water saturatedreservoir rock 302 and is received by one or more receivers 310positioned in a receiver borehole.

As shown in FIG. 3, the EM energy 306 that transits through the watersaturated reservoir rock 302 may transit through the water saturatedreservoir rock 302 at a time (t) of x (t=x). FIG. 3 also depicts aportion of the water saturated reservoir rock 302 injected with aninjection fluid having a contrast agent (depicted by region 312). Asopposed to the EM energy 306, the EM energy 308 that travels through theinjection fluid having the contrast agent 312 in addition to portions ofthe water saturated reservoir rock 302 has a total transit time ofsignificantly greater than x (t>>x). Thus, as described in thedisclosure, the use of a contrast agent may increase the contrastbetween the injection fluid and water saturated reservoir rock.

As described in the disclosure, the contrast agent used in the injectionfluid in EM surveying may have a dielectric constant (also referred toas relative electric permittivity ε_(r)) greater than water saturatedreservoir rock to improve the resolution of the contrast agent from thereservoir. A typical water saturated reservoir rock may have adielectric constant of about 3.5. Conventional high dielectric materialsmay have a dielectric constant in the range of about 3.5 to about 100and may not exhibit a significant enough contrast with the watersaturated reservoir rock, especially when such high electric materialsare in solution (that is, in the injection fluid).

Accordingly, embodiments of the disclosure include conducting EMsurveying using “giant” dielectric materials. As used in the disclosure,the term giant dielectric refers to materials having a dielectricconstant of at least 10000 in the 1 Hz to 1 MHz frequency range. By wayof example, such giant dielectric materials may include calcium coppertitanate (CCTO) and other A-Cu3Ti4O12 compounds (where “A” includes atrivalent rare earth element, such as Ce, Eu, Gd, Tb, Yb, or may includeBi), doped nickel oxides (for example, nickel oxides doped with Li, Ti,Fe, or V), doped cupric oxides (for example, cupric oxides doped withTa, Ca, or Ba), barium titanate, and bismuth strontium titanate.

In some embodiments, an injection fluid may include an aqueous fluid anda contrast agent having giant dielectric nanoparticles. In someembodiments, the aqueous fluid may be fresh water (water havingrelatively low (that is, less than 5000 parts-per-million by mass (ppm))concentrations of total dissolved solids (TDS)) or seawater (forexample, water having a salinity in the range of about 30,000 to about40,000 ppm TDS). In some embodiments, the aqueous fluid may includeartificial brines, natural brines, brackish water, or formation water.In some embodiments, the giant dielectric nanoparticles may be presentin an amount in the range of about 1 w/w % to about 10 w/w %. In someembodiments, the amount of giant dielectric nanoparticles may beselected based on the pH of the injection fluid and the type ofnanoparticle. Advantageously, the injection fluid having the giantdielectric nanoparticles may provide a significantly greater contrast towater saturated rock or connate water as compared to existing injectionfluids.

FIG. 4 depicts a process 400 for imaging a reservoir using giantdielectric nanoparticles in accordance with an embodiment of thedisclosure. Initially, an injection fluid may be prepared from anaqueous fluid and a selected giant dielectric material as a contrastagent (block 402). As discussed in the disclosure, suitable giantdielectric materials may include nanoparticles of the followingmaterials; calcium copper titanate (CCTO) and other A-Cu3Ti4O12compounds (where “A” includes a trivalent rare earth element, such asCe, Eu, Gd, Tb, Yb, or may include Bi), doped nickel oxides (forexample, nickel oxides doped with Li, Ti, Fe, or V), doped cupric oxides(for example, cupric oxides doped with Ta, Ca, or Ba), barium titanate,or bismuth strontium titanate. In some embodiments, the giant dielectricnanoparticles may be in an amount in the range of about 1 w/w % to about10 w/w %. The giant dielectric nanoparticles may be mixed with theaqueous fluid using known mixing techniques to prepare the injectionfluid at the surface.

The injection fluid having the contrast agent may be introduced into areservoir of interest (block 404) using techniques known in the art. Forexample, in some embodiments, the injection fluid may be pumped into aninjection well in fluid connection with a producing well, such as in awaterflooding operation.

Next, EM energy may be emitted into the reservoir (block 406), such asvia EM energy pulses from one or more transmitters. For example, one ormore transmitters may be positioned in a transmit borehole to emit EMenergy into a reservoir. In some embodiments, the transmit borehole maybe a borehole of an injection well (for example, the injection well usedto introduce the injection fluid) or a producing well. In someembodiments, the one or transmitters may be a transmitter array. In someembodiments, the one or more transmitters may be a single transmitterthat is repositioned at different positions in the transmit borehole forthe emission of EM energy. The EM energy pulses may be emitted atfrequencies selected based on the size of the area being surveyed.

The EM energy pulses may be received at one or more receivers, and thetransit time of the emitted EM pulses may be measured (block 408). Forexample, as discussed in the disclosure, in some embodiments one or morereceivers may be positioned in a receiver borehole (for example, aborehole of an injection well or a producing well) to provide forcross-well (borehole-to-borehole) measurements. In other embodiments,one or more receivers, such as a receiver array, may be positioned at asurface above the transmit borehole, to provide for borehole-to-surfacemeasurements. In some embodiments, both cross-well andsurface-to-borehole techniques may be used to analyze a reservoir ofinterest. In some embodiments, other characteristics of the received EMenergy pulses may be determined. For example, in some embodiments thesignal strength (for example, amplitude or power) as a function offrequency of the EM energy pulses may be determined.

An image of the position of the injection fluid through the subsurfacehydrocarbon recover may be generated from the transit time (block 410).For example, the transit time may be used to generate a two-dimensional(2-D) spatial map of the position of the injection fluid at any timeduring a waterflooding operation. The image may be generated byperforming an inversion of the transit time data using inversiontechniques known in the art. In some embodiments, as known in the art,other characteristics of the EM energy pulses, such as signal strengthas a function of a frequency, may be used during the inversion toimprove the generated image.

The image may enable an identification of the subsurface features in thereservoir, such as by further analysis of the transit time (block 412).In some embodiments, paths in the reservoir that are permeable to theinjection fluid may be identified. Additionally, the use an injectionfluid having a contrast agent as described in the disclosure may enablethe injection fluid to be distinguished from a different previouslyinjected injection fluid or other fluids present in the reservoir.

Ranges may be expressed in the disclosure as from about one particularvalue, to about another particular value, or both. When such a range isexpressed, it is to be understood that another embodiment is from theone particular value, to the other particular value, or both, along withall combinations within said range.

Further modifications and alternative embodiments of various aspects ofthe disclosure will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the embodiments described inthe disclosure. It is to be understood that the forms shown anddescribed in the disclosure are to be taken as examples of embodiments.Elements and materials may be substituted for those illustrated anddescribed in the disclosure, parts and processes may be reversed oromitted, and certain features may be utilized independently, all aswould be apparent to one skilled in the art after having the benefit ofthis description. Changes may be made in the elements described in thedisclosure without departing from the spirit and scope of the disclosureas described in the following claims. Headings used described in thedisclosure are for organizational purposes only and are not meant to beused to limit the scope of the description.

What is claimed is:
 1. A method of electromagnetic imaging of asubsurface hydrocarbon reservoir, comprising: introducing an injectionfluid into the subsurface hydrocarbon reservoir, the injection fluidcomprising a contrast agent comprising a plurality of giant dielectricnanoparticles, wherein the plurality of giant dielectric nanoparticleshave a dielectric constant of at least 10000 at a frequency in the rangeof 1 hertz (Hz) to 1 megahertz (Mhz); emitting pulses of electromagneticenergy from a subsurface borehole to travel through the subsurfacehydrocarbon reservoir; determining the transit time of the emittedpulses of electromagnetic energy from a plurality of electromagneticsensors, wherein the transit time of the emitted pulses through theinjection fluid is greater than the transit time of the emitted pulsesthrough the subsurface hydrocarbon reservoir absent the injection fluid;and generating an image of the position of the injection fluid throughthe subsurface hydrocarbon reservoir based on the determined transittime.
 2. The method of claim 1, wherein the plurality of giantdielectric nanoparticles comprise nanoparticles of A-Cu3Ti4O12, whereinA is selected from the group consisting of Ce, Eu, Gd, Tb, Yb, and Bi.3. The method of claim 1, wherein the plurality of giant dielectricnanoparticles comprise nanoparticles of at least one of copper titanate(CCTO), a doped nickel oxide having a dopant selected from the groupconsisting of Li, Ti, Fe, and V, a doped cupric oxide having a dopantselecting from the group Ta, Ca, and Ba, barium titanate, and bismuthstrontium titanate.
 4. The method of claim 1, wherein the plurality ofgiant dielectric nanoparticles comprise an amount in the range of 1weight % of the total weight (w/w %) to 10 w/w %.
 5. The method of claim1, wherein the injection fluid comprises an aqueous fluid.
 6. The methodof claim 1, wherein emitting pulses of electromagnetic energy from asubsurface borehole to travel through the subsurface hydrocarbonreservoir comprises emitting of electromagnetic energy from at least onetransmitter positioned in the subsurface borehole.
 7. The method ofclaim 1, wherein the subsurface borehole comprises a first subsurfaceborehole, wherein the plurality of electromagnetic sensors arepositioned in a second subsurface borehole.
 8. The method of claim 1,wherein the plurality of electromagnetic sensors are positioned on thesurface.
 9. The method of claim 1, wherein the image comprises a 2-Dspatial map.
 10. The method of claim 1, wherein generating an image ofthe position of the injection fluid through the subsurface hydrocarbonreservoir based on the determined transit time comprises performing aninversion of the determined transit time.
 11. The method of claim 1,comprising forming the injection fluid by mixing an aqueous fluid withthe plurality of giant dielectric nanoparticles.
 12. The method of claim1, comprising identifying a subsurface feature in the subsurfacehydrocarbon reservoir based on the image.
 13. An injection fluidcomposition for the imaging of a subsurface hydrocarbon reservoir,comprising: an aqueous fluid; and a contrast agent comprising aplurality of giant dielectric nanoparticles, wherein the plurality ofgiant dielectric nanoparticles have a dielectric constant of at least10000 at a frequency in the range of 1 hertz (Hz) to 1 megahertz (Mhz).14. The composition of claim 13, wherein the plurality of giantdielectric nanoparticles comprise nanoparticles of A-Cu3Ti4O12, whereinA is selected from the group consisting of Ce, Eu, Gd, Tb, Yb, and Bi15. The composition of claim 13, wherein the plurality of giantdielectric nanoparticles comprise nanoparticles of at least one ofcopper titanate (CCTO), a doped nickel oxide having a dopant selectedfrom the group consisting of Li, Ti, Fe, and V, a doped cupric oxidehaving a dopant selecting from the group Ta, Ca, and Ba, bariumtitanate, and bismuth strontium titanate.
 16. The composition of claim13, wherein the plurality of giant dielectric nanoparticles comprise anamount in the range of 1 weight % of the total weight (w/w %) to 10 w/w%.
 17. The composition of claim 13, wherein the aqueous fluid comprisesfresh water or seawater.